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1.
The Pantanal floodplain of southwestern Brazil, with its mosaic of marshes,seasonally flooded savannas, woodlands and forests, is known as one of thewildlife hotspots of South America. The region harbors a rich mammal fauna andis a stronghold for a number of mammal species; however, still very few thoroughmammal surveys have been conducted in the Pantanal. This is the first mammalsurvey from the southeastern part of the region. An intensive,three-month study of the medium to large, non-volant species wasconducted at a location in the upper Rio Negro Basin, Aquidauana region, MatoGrosso do Sul. Thirty species of mammals were recorded, including 5 xenarthrans,1 primate, 10 carnivores, 7 ungulates and 5 caviomorph rodents. It was possibleto analyze the field biology of many of the species to a level not previouslypublished for the Pantanal. Recommendations are given for camera trapping in thePantanal and the Amazon. Finally, the effects of intensive cattle ranching onconservation in the Pantanal are discussed.  相似文献   

2.
The knowledge on the geographical distribution of species is essential for building biogeographical and macroecological hypotheses. However, information on this regard is not distributed uniformly in space and usually come from biased sampling. The aim of this study is to quantify the influence of spatial distribution of sampling effort on the assessment of spider species richness in Brazil. We used a database of spider distribution records in Brazil, based on the taxonomic and biodiversity survey literature. The results show that the Atlantic Forest was better sampled and had the highest spider species richness among the Brazilian biomes. The Amazon, though having large collecting gaps and high concentration of records around major cities and rivers, showed the second highest number of species. The Pampa had a large number of records, but these are concentrated near a major city in the transition zone with the Atlantic Forest. The Cerrado, Caatinga and Pantanal had shown to be poorly sampled and, consequently, were among the lesser known biomes regarding the spider fauna. A linear regression analysis showed that the spider species richness in Brazil is strongly correlated to the number of records. However, we have identified areas potentially richest in species, which strongly deviate from the predicted by our analyses. Our results show that it is possible to access the spatial variation in species richness, as long as the variation in sampling effort is taken into account.  相似文献   

3.
Evaluation of the lichen flora of the Northern Andes must be based on a restricted number of better-known groups, probably less than 25% of the flora. This is because our knowledge of the taxonomy and distribution of lichens in the Tropics is still very incomplete. In the Andes, the groups with foliose and fruticose growth forms are particularly well represented; the crustose group seems less important. This is in contrast with the surrounding lowlands, where crustose is the dominant growth form. At higher taxonomic levels there is a resemblance in taxonomic composition with the cooler zones of the world, which disappears at the generic or sectional levels. A conspicuous morphological feature is the frequency of foliose lichens with linear, rhizinate, or ciliate lobes, probably an adaptation to very humid conditions. More than half of the species have a wide distribution throughout the Tropics or at least in the Neotropics. Among the more restricted taxa is a humid montane element. At the highest elevations a temperate element is apparent, usually with bicentric distribution in both hemispheres. Perhaps 10% of the species are known only from the region; local endemism is probably very scarce. A few taxa appear to be restricted to Ecuador and southern Colombia or Venezuela; so far, only a single species is known with certainty to be restricted to the humid paramos of Colombia. There are distinct affinities with the lichen flora of southeastern Brazil and the Caribbean-Central American area but not with the adjacent Guayana Highland.  相似文献   

4.
While the diversity and distribution of macro-organisms living in phytotelmata (plant-container habitats) is well known, detailed taxonomic work on micro-organisms living in the same environments is limited. As a model clade of microbial eukaryotes, sampling of ciliates in Neotropical bromeliad tanks increased, and Neotropical phytotelmata such as bamboo stumps and tree holes were newly sampled. Thirty-three isolates from Brazil, Costa Rica, Dominican Republic, Jamaica and Mexico were sequenced for small subunit rDNA, and placed into a phylogenetic context using non-phytotelmata GenBank accessions. This and the morphological investigations discovered 45 undescribed, possibly endemic ciliate species. The potential endemics are from throughout most clades of the ciliate tree of life, and there is evidence of speciation within the Neotropical phytotelmata habitat. Our data show the number of potential Neotropical phytotelmata-endemic ciliate species increasing as more phytotelmata are sampled. While the new data show that the supposed endemics are mainly recruited from moss and ephemeral limnetic habitats, the bromeliad ciliate fauna is quite distinct from those of other limnetic habitats, lacking many typical and common freshwater genera, such as Coleps, Colpidium, Frontonia, Paramecium, Glaucoma, Nassula, Stylonychia and Trithigmostoma. There is no indication that specific ciliates are confined to specific bromeliads.  相似文献   

5.
This study provides data on the length‐weight relationships (LWR) for 26 tropical fish species collected in August 2010 (dry season) and May 2011 (wet season), and represents the first LWR references for these species in the small tributary streams flowing into the major rivers of the Pantanal Matogrossense, Brazil.  相似文献   

6.
The Paripe river estuary is located in Itamaracá Island, north coast of Pernambuco, northeastern Brazil. Its Crustacea Decapoda fauna was studied during several years. In the estuary there are mangroves, mud- and sandbanks, and tidal creeks. The fauna comprises a total of 64 species in 20 families. The coexistence of these species confirms the ecological importance of this small estuary, only 1.6 km long and 0.5 km wide. The ecology of each species in the estuary is presented.  相似文献   

7.
The composition of the rumen ciliate fauna in 76 Kafue lechwe inhabiting a limited area in Zambia was surveyed and five genera containing 24 species with 16 formae belonging to the family Ophryoscolecidae were identified. Four new species belonging to Diplodiniinae were recognized and described as Diplodinium lochinvarense n. sp., Diplodinium leche n. sp., Diplodinium zambiense n. sp., and Metadinium ossiculi n. sp. In addition, Ostracodinium gracile form fissilaminatum Dogiel, 1932 was found for the second time and described as Metadinium fissilaminatum n. comb. The species composition was fairly unusual. Seven of the species have been found only in African wild antelopes and these species were found more frequently than cosmopolitan species. There was no evidence of isotrichid species. The average density of ciliates per 1 ml of the rumen fluid was 25.7 x 10(4), and the number of ciliate species per head of host was 10.8.  相似文献   

8.
Limnoperna fortunei (Bivalvia, Mytilidae), a freshwater bivalve native to Southern Asia, has been an invasive species in South America since 1991. It spread upstream in the La Plata basin reaching the Paraguay River in the vicinity of the Pantanal wetland, Brazil, around 1998. The role of abiotic factors in controlling establishment and abundance of this species is not well known, making projections of its risk of further spread difficult. This study evaluates the importance of abiotic factors to L. fortunei populations established in rivers of the Pantanal, focusing on larval and juvenile densities and taking advantage of a wide range of seasonal variability in water temperature, flow, dissolved oxygen, and suspended material. Temperature, river stage (influencing several water characteristics) and water velocity are the main variables related to the larval and juvenile densities. In the Pantanal, environmental variables vary over a broader range compared with other South American locations, subjecting L. fortunei to oxygen depletion, low calcium, low pH, and high water velocity and suspended solids, associated with low chlorophyll a concentrations. The combined effect of several of these conditions may explain the relatively low densities in some Pantanal sites. However, they probably will not prevent the persistence of populations in the Pantanal and the eventual establishment of viable populations in upriver systems connected to the Pantanal. These results are pertinent not only to this species but also to other aquatic invasive invertebrates whose expansion may be limited by thermal extremes, episodic oxygen depletion, and waters that are too dilute or acidic for optimal biocalcification.  相似文献   

9.
Objectives of this study are to summarize the current state of knowledge of the diversity and distribution of Collembola in Brazil; to identify areas of most importance, interest, and need of additional research; and to enable development of experimental hypotheses for future research on Collembola in this region. The total number of collembolan species currently known from Brazil is 199, distributed among 19 families and 80 genera. The greatest numbers of species have been recorded from the states of Rio de Janeiro and Amazonas (with 69 and 56 species, respectively). Few or no species are known from most Brazilian states. Most of the species for which specific Brazilian environmental habitat information is available (93, 66%) are known only from forest environments. Most of the species (127, 64%) are known only from Brazil (most likely being endemic); 33 species (17%) are known only from Brazil and other neotropical areas; and 39 species (20%) have a distribution beyond the neotropical region. Results of this study indicate that much remains to be learned about the Brazilian collembolan fauna. This is especially true for areas of the northeastern, central-western, and southern regions. Studies to determine the species composition of collembolan communities in specific environments in Brazil are needed. The great diversity of Collembola species in Brazil is largely unknown and there are many opportunities for additional research on these environmentally important organisms in this area. Such additional research on the Collembola in Brazil is also essential for a better understanding of the neotropical (and world) collembolan fauna.  相似文献   

10.
Mammals in South American drylands: faunal similarity and trophic structure   总被引:1,自引:0,他引:1  
We compared the fauna of small mammals (less than 500 g body weight) among five major South American drylands (Atacama, Altiplano, Monte, Patagonia and Caatinga) and found considerable heterogeneity and distinctiveness in species richness and composition between these biomes. From a total of 89 recorded species, 76 of them are restricted to only one of these drylands. The highland desert, or Altiplano, is the biome with the highest number of species. Despite the marked differences in the composition of the mammalian fauna, the trophic structure shows a rather consistent pattern: herbivores are the most important trophic group in all drylands. This consistency seems to be more the result of phylogenetic inertia than of similar ecological processes. Our results are compared with recent studies on desert small mammals across continents.  相似文献   

11.
ABSTRACT The composition of the rumen ciliate fauna in 76 Kafue lechwe inhabiting a limited area in Zambia was surveyed and five genera containing 24 species with 16 formae belonging to the family Ophryoscolecidae were identified. Four new species belonging to Diplodiniinae were recognized and described as Diplodinium lochinvarense n. sp., Diplodinium leche n. sp., Diplodinium zambiense n. sp., and Metadinium ossiculi n. sp. In addition, Ostracodinium gracile form fissilaminatum Dogiel, 1932 was found for the second time and described as Metadinium fissilaminatum n. comb. The species composition was fairly unusual. Seven of the species have been found only in African wild antelopes and these species were found more frequently than cosmopolitan species. There was no evidence of isotrichid species. The average density of ciliates per 1 ml of the rumen fluid was 25.7 times 104, and the number of ciliate species per head of host was 10.8.  相似文献   

12.
The phlebotomine fauna is highly varied in Três Bra?os, an endemic area of american cutaneous leishmaniasis, situated in the cacao growing region in the southeast of Bahia State, Brazil. Thirty spécies of the Lutzomyia genus were identified in 13,535 specimens collected between 1976 and 1984. Lutzomyia whitmani was the dominant species accounting for 99% of flies in the peridomicile and 97.5% of those caught in homes. In the forest the predominant species were Lu. ayrozai and Lu. yuilli. Lu. whitmani accounted for only 1.0% of the specimens examined. Lu. flaviscutellata, the proven vector of Leishmania mexicana amazonensis, was also collected in small numbers. Lu. wellcomei, a known vector of L. braziliensis braziliensis in the Serra dos Carajás, Pará, Brazil was not encountered in the Três Bra?os region where the parasite causing human infections is usually L.b. braziliensis. Although we have not encountered a natural infection with leishmanial promastigotes in 1,832 females of the various species examined, we discuss the probability that Lu. whitmani is the vector of L.b. braziliensis in the region maintaining transmission in dogs and man.  相似文献   

13.
Thrichomys apereoides, a caviomorph rodent species common in a highly endemic area for Chagas disease in Brazil, may act as reservoir of the parasite. However, no information is available concerning its sibling species Thrichomys pachyurus, found in the Pantanal region, where Trypanosoma cruzi is found only in the enzootic cycle. We followed up the cross infection of these cryptic species with two isolates derived from naturally infected T. pachyurus and Thrichomys apereoides laurentius. No regional co-adaptation between Thrichomys species and the regional isolates were noticed. However, significant differences in the outcome of the infection were observed. T. a. laurentius was more resistant than T. pachyurus, as expressed by lower parasitemia and less histopathological damage. The routine biochemical markers used for laboratory rodents were unsuitable for follow up of infection in Thrichomys spp, since they did not correlate with the histopathological findings or allowed the kinetic follow-up of tissue colonization by the parasite.  相似文献   

14.
The Pantanal is one of the faunistic provinces considered as a priority area for invertebrate conservation. However, it is one of the areas in Brazil where the local fauna is less assessed, thus needing more scientific information that could allow political decisions to be made regarding conservation. The continuous pressure for new pasture areas leads to improper habitat occupation and destruction, like fragmentation of forest areas in the region. Such alterations can cause different impacts on the local fauna, including the soil arthropods. The main objective of this work was to compare the morphospecies composition, diversity and density of the soil arthropod fauna between a secondary single species forest (Cambarazal) and a cultivated pasture with exotic and native grass species, using only pitfall traps as sampling method. We found a great variation on the vegetal cover among environments. A higher humidity in the forest soil was observed, as well as a greater compaction of the soil in the cultivated pasture. A total of 3635 individuals were collected, belonging to 214 different morphospecies. 139 morphospecies were collected in the forest (37% exclusive to this environment), while 134 morphospecies were collected in the cultivated pasture (35% exclusive). The diversity was higher in the forest (H′ = 1.634) than in the cultivated pasture (H′ = 1.253). However, considering the area as a whole (forest and pasture) the global diversity was increased. In this paper we discuss about the effects of environmental changes on soil arthropod diversity and propose a hypothetical model for invertebrate management in mosaic ecosystems.  相似文献   

15.
The Hyacinth Macaw (Anodorhynchus hyacinthinus) is one of 14 endangered species in the family Psittacidae occurring in Brazil, with an estimated total population of 6,500 specimens. We used nuclear molecular markers (single locus minisatellites and microsatellites) and 472 bp of the mitochondrial DNA control region to characterize levels of genetic variability in this species and to assess the degree of gene flow among three nesting sites in Brazil (Pantanal do Abobral, Pantanal de Miranda and Piauí). The origin of five apprehended specimens was also investigated. The results suggest that, in comparison to other species of parrots, Hyacinth Macaws possess relatively lower genetic variation and that individuals from two different localities within the Pantanal (Abobral and Miranda) belong to a unique interbreeding population and are genetically distinct at nuclear level from birds from the state of Piauí. The analyses of the five apprehended birds suggest that the Pantanal is not the source of birds for illegal trade, but their precise origin could not be assigned. The low genetic variability detected in the Hyacinth Macaw does not seem to pose a threat to the survival of this species. Nevertheless, habitat destruction and nest poaching are the most important factors negatively affecting their populations in the wild. The observed genetic structure emphasizes the need of protection of Hyacinth Macaws from different regions in order to maintain the genetic diversity of this species.  相似文献   

16.
The breeding system of Eichhornia azurea (Pontederiaceae) has been described as being both self- and heteromorphic incompatible based on crossing experiments performed on plants grown in an experimental garden. We studied the breeding system of tristylous E. azurea population under natural conditions in the Pantanal wetlands, Brazil. Controlled pollinations were conducted using 35 individuals of each floral morph. Legitimate pollinations produced more fruits than self- and illegitimate pollinations, except for the mid-styled morph which was highly self- and heteromorphic compatible. The number of seeds per fruit was higher under legitimate pollinations than in the other treatments, but self- and illegitimate pollinations produced more fruits and seeds in the Pantanal than for individuals of E. azurea in other populations. The higher fruit and seed production resulting from legitimate pollinations corroborate previous studies, but self-compatibility of mid-styled plants was not previously reported. Overall results indicate a partially self- and heteromorphic compatible system for this species in the Pantanal.  相似文献   

17.
ABSTRACT. Composition of rumen ciliate fauna in five Zambian, sassaby antelopes was determined. Six genera, 18 species, and four forms were identified. One new species and form, belonging to the subfamily Diplodiniinae, were found, then labeled Ostracodinium damaliscus n. sp. and Diplodinium bubalidis f. aspinosum n. f., respectively. Only ophryoscolecid species were present while isotrichids were absent. Twelve of 18 total species are commmonly found in African antelopes. Three of those 12 species, Entodinium fyferi, Enoploplastron garstangi and Opisthotrichum janus , are only found in African antelopes. Percentage composition was low in the genera ml of rumen fluid, and the average number of ciliate species per host was 17.2.  相似文献   

18.
Ants are a dominant group in tropical savannas and here we examined the responses of the arboreal and ground‐dwelling ant fauna to a fire in a Neotropical savanna (cerrado) reserve in Central Brazil. Ants were collected using pitfall traps and baits placed in trees and on the ground beneath each tree. Of the 36 trees marked along two transects, half (from each transect) were burned and half not. The same trees were sampled 1 wk before and again 3 and 12 mo after the fire. Rarefaction curves and ordination analyses using data from all trees from each side of each transect indicated that overall ant species richness and composition did not change after fire. Fire, however, reduced the mean number of ant species per tree, and increased the mean number of species on the ground. Fire increased the average abundance of specialist predators, Camponotini, and opportunistic species, and decreased that of arboreal specialists. Changes in the ground‐dwelling fauna were only detected 12 mo after the fire, while those in the arboreal fauna occurred earlier and were no longer apparent 12 mo after the fire. We suggest that these contrasting results represent mainly an indirect response of the ant communities to fire‐induced changes in vegetation. Given the temporary and small scale nature of the effects detected and the overall resilience of the ant fauna, our results indicate that a single fire in the cerrado vegetation does not greatly impact the structure of ant communities in the short term.  相似文献   

19.
Species composition and distribution of large intestinal ciliates were investigated in the feces from 15 Turk rahvan horses, living in the vicinity of Izmir, Turkey. Twenty-two ciliate genera consisting of 36 species were identified. This is the first report on intestinal ciliates in Turk rahvan horses and no previously unknown species were observed. The mean number of ciliates was 14.2 ± 13.9 × 104 cells ml−1 of feces and the mean number of ciliate species per host was 9.9 ± 7.1. No ciliates were observed in 2 horses. Bundleia and Blepharocorys were considered to be the major genera since these ciliates were constantly found in high proportions. In contrast, Paraisotricha, Didesmis and Gassovskiella were only observed at low frequencies. The ciliates found in this survey had almost the same characteristics as those described in previous reports, suggesting that there was no significant geographic variation in the intestinal ciliate fauna of equids.  相似文献   

20.
Rumen ciliate species composition was surveyed in domestic yaks kept in Tibet, Sichuan, and Inner Mongolia, China. Twelve genera including 36 species with 18 formae were identified. The species compositions were slightly different among the three areas: yaks in Tibet had the simplest fauna, in contrast, the fauna of yaks in Inner Mongolia were the most abundant and similar to those found in the cattle kept in the same area. This suggests that the rumen ciliate composition of yaks is affected by that of cattle kept together or in proximity. A new species belonging to the genus Entodinium, Entodinium monuo n. sp., was recognized from the yaks in all areas. This new species was common in the yaks but was not detected in the cattle fed near yaks in Inner Mongolia. There was a similar generic ciliate composition in yaks kept in respective areas. Entodinium was the most predominate ciliate (51.9-61.0%) with total ciliate densities estimated as 10(5)/ml per yak.  相似文献   

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